Coaxial cable is an electrical cable consisting of an inner signal conductor, an insulator surrounding the signal conductor, and an outer cylindrical conducting shield surrounding the insulating spacer such that the inner conductor and the outer shield shares the same axis.
The coaxial cable is often used for precise electric and electronic devices and test devices due to its low electrical interference and transmission stability relative to other types of cables. In a case of usage with a test device, a coaxial connecting device for securing signal transmission reliability of the coaxial cable even with repeated attachment and detachment to the test objects.
FIG. 1 shows a conventional coaxial connecting device. As shown in FIG. 1, the conventional coaxial connecting device includes an inner conductive contact assembly contacting a signal conductor of a coaxial cable, a conductive ground plunger containing the inner conductive contact assembly in its cylindrical inner space, an isolator for electrically isolating the inner conductive contact assembly and the conductive ground plunger from each other, and an interface element fixed to an outer conductor of a coaxial cable so as to make electrical connection to the plunger. The interface element is arranged in an exterior barrel by means of a ground sleeve such that the ground sleeve slides along the interface element fixed inside the exterior barrel.
In the conventional coaxial connecting device, however, the interface element is fixed on the exterior barrel such that, when approaching the exterior barrel to a test object without cutting off the electricity on the coaxial cable, the contact assembly and ground plunger are likely to contact the conductors of the test object before fixing the exterior barrel in place so as to cause unstable electric current, whereby it is required to laboriously switch on and off the electricity whenever changing test target devices.
Meanwhile, a connection member is required for electrically connecting the test equipment, which generates test signals, to a test target device. Particularly, as the devices to be tested are highly advanced, the connection link vulnerable to weak signals and interferences causes to degrade the test result reliability.
Therefore, there has been a requirement for a coaxial connecting device capable of transferring test signals to test target device, without degrading the signal strength and causing frequency interferences.